Printing apparatus.



B.F.BBRRY. PRINTING APPARATUS.

Patented Aug, 24, 1909.

UNITED STATES PATENT ornrcn.

BENJAMIN F. BERRY, OF ST. LOUIS, MISSOURI.

PRINTING APPARATUS.

Specification of Letters Patent.

Application filed November 2, 1908. Serial No. 460,643. I

T 0 all whom it may concern:

Be it known that I, BENJAMIN F. BERRY, a citizen of the United States of America, residing in the city of St. Louis and State of Missouri, have invented certain new and useful Improvements in Printing Apparatuses, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to a printing apparatus designed for service in the use of zinc or other etched or printing surfaced plates used in combination with an impression cylinder and in lieu of lithographing stones.

It has been the common practice heretofore in lithographic printing to use lithographic stones upon which the printing surfaces are produced and, due to the expense of such stones and the expense of producing the printing surfaces thereon, numerous attempts have been made to utilize sheets of metal, such as zinc, which were etched to produce the printing surfaces thereon and then mounted upon carriages or beds to serve as supports for the sheets during the printing operations. In so far as I am aware all of such attempts have proven unsatisfactory and this result has been due to the fact that it was found impossible to stretch the sheets of etched or printing surfaced material in a flat condition upon the carriages or beds to which they were applied by reason of the inherent tendency of the sheet material to bulge or bow away from the support beneath it with the consequence of producing an unsuitable printing form susceptible of yielding when subjected to pressure from the impression cylinder of a printing press and making it absolutely impossible to secure satisfactory impressions from the printing form. By my improvement I make it possible to utilize printing form sheets that are attached to a supporting bed or carriage in bowed conditions which it is natural for them to assume and in which they will rest firmly upon their supports and provide a track for such supports having a curved or upwardly bulged runway surface corresponding approximately to the curve or bulge of the form sheets whereby the form sheets and their support are caused to travel in an arc of a circle beneath the impression cylinder and corresponding relative positions between the impression cylinder and the printing form are constantly maintained during printing operations.

Figure 1 is a longitudinal vertical sectlon illustrating my invention. Fig. 2 is a cross section taken through my apparatus.

In the accompanying drawings :1 desig nates an impression cylinder that may be of any construction usual to printing presses.

2 designates a printing press bed or carriage that is adapted to operate to and fro beneath the impression cylinder 1 and is provided with a curved top. face 3 upon which the printing form sheet A of zlnc or other suitable sheet material is laid to lie firmly in a curved position corresponding to the curvature of said top surface. The printing form sheet may be secured to the bed on which it is laid by any suitable means, such, for instance, as a strip 4 seated upon the sheet at one end of the bed and secured in position by screws or other suitable means, while the other end of the printing form sheet is entered into a groove 5 at the second. end of the bed and held in said groove by a clamp strip 6 that is forced into tight impingement with the printing form sheet by as many set screws 7 as may be requlred to hold the end of the printing form sheet from escape from the groove in the binding strip. At the lower side of the bed 2 are runners 8 which are'curved from their ends toward their centers, the degree of curvature in each runner corresponding approximately to the degree of curvature at the top surface of the bed 2 and the printing form sheet laid upon said bed.

The bed 2 is supported by a track preferably comprising a pair of rails 9 suitably supported, and the top surfaces 10 of which are curved longitudinally and upwardly from their ends toward their centers, the curvature of said top surfaces corresponding approximately to the curvature at the top surface of the bed 2 and at the bottom surfaces of the bed runners 8.

In the practical use of my printing apparatus, the bed 2 is reciprocated during printing operations to and fro upon the track beneath it, and as it is so reciprocated it moves in an arc of a circle beneath the impression cylinder so that the printing surface upon the printing form sheet on said bed is constantly maintained at all times in the same elevation relative to the impression cylinder, notwithstanding the curvature in the print- Patented Aug. 24, 1909.

ing form sheet and as a consequence the printing action is made uniform throughout the entire printing surface of the form sheet.

I claim 1. A printing apparatus comprising a curved track, a printing form carriage operable to and fro on said track, and a cylinder opposing said printing form carriage.

2. A printing apparatus comprising an upwardly curved track, a printing form carriage operable to and fro on said track, and a cylinder operable above and opposing said carriage.

3. A printing apparatus comprising a track curved upwardly from its ends to the center thereof, a printing form carriage operable to and fro on said track, and a cylinder operable above and opposing said carriage.

4:. A printing apparatus comprising a curved track, a printing form carriage having a runner operable to and fro on said track, and a cylinder operable above and opposing said carriage.

5. A printing apparatus comprisin an upwardly curved track, a printing orm carriage operable to and fro on said track and having an upwardly curved upper surface adapted to receive a printing form sheet, and a cylinder operable above said carriage. I

6. A printing apparatus comprising an upwardly curved track, a carriage having an upwardly curved top surface adapted to receive a printing form sheet and having an upwardly curved runner adapted to operate to and fro upon said track, and a cylinder operable above said carriage.

BENJAMIN F. BERRY. In the presence of HOWARD G. (1001;, EDNA B. LINN. 

